Hydroelectric turbine installations of the type illustrated in FIG. 1 conventionally include a power generating unit having a longitudinal axis 10, the unit consisting of an electric generator 12 and associated hydro-turbine 14. The hydro-turbine comprises a runner 16 having a hub 18 and a plurality of runner blades 20 connected to the hub. The runner is rotatably mounted within a casing or passageway 22 in which water flows from an upper elevation source in fluid communication with an inlet port 24 to a lower elevation discharge region or outlet port 26. Water passing through the passageway imparts a rotating movement to the runner, which when transmitted to the generator causes the generator to produce electrical energy. Turbine 14 also includes various water closure components or covers 27 to contain the water so that it does not escapee and guide the water so that it can be utilized for the intended purposes. Hydro-electric installations also often include associated components such as wicket gates 28 which are designed to regulate the amount of water flowing through the passageway and, accordingly, the quantity of electrical energy produced by the generator.
For proper operation of the hydroelectric turbine installation the turbine will need to be securely positioned and rotatably guided within the passageway. As can be readily appreciated by those skilled in the art, accurately and reliably guiding the turbine in rotation within the passageway permits the reduction of dimensional clearances between the tip of the blades and the passageway. This will limit efficiency losses caused by water leaking between the passageway and the tip of the blades.
Similarly, the generator, which is connected to the turbine shaft 30, will have to be laterally guided relative to the passageway. The lateral guiding of the generator is typically achieved by a generator guide bearing 32 which is commonly attached to structural components such as guiding brackets or frames 34, or the like, these structural components being themselves anchored to concrete decks 36. The hydroelectric unit is also ordinarily supported in the direction of axis 10 by a thrust bearing 38. However, because of the size and weight of hydro-turbine installations, and to allow such installations to withstand the axial thrust applied to them by the water travelling through the passageway, the structural components and decks that guide and support the installation axially and radially will typically be relatively massive.
Furthermore, generator guide bearing brackets, bridges, or frames are typically disposed at a relatively significant distance from the inlet port 24 of the passageway. This will naturally increase the length and weight of the turbine shaft, necessitating the use of sturdy brackets, bridges, or frames to properly provide lateral support to the generator. This will also require massive concrete decks to separate the generator from the turbine.
In light of the foregoing, although it is widely recognized that hydro-electric turbine installations provide a very useful form of production of energy in certain cases the complexity and associated cost of these massive support brackets, decks, and other structures, or the space required to erect them, will prevent the otherwise desirable use of such installations. Accordingly, it has become highly desirable to provide effective ways to overcome these shortcomings without materially impairing the operating characteristics of these hydroelectric installations.